<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>


        div{
            width: 500px;
            height: 200px;
            background: green;
            border-radius: 30px;

        }

        /* 长方形 建议px */
        

    </style>

</head>
<body>
    
    <div></div>

</body>
</html>